Last year sources told the Christian charity Open Doors that her sentence had been made longer. They also described how the severity of conditions inside the notorious Evin Prison have contributed to the severity of her medical problems.

Maryam was sentenced to four years in prison after her arrest in January 2013 in connection with work on an orphanage she did with Saeed Abedini, an American former Muslim who converted in 2000.

Abedini, active in the underground house church movement in Iran, was also imprisoned in Evin. He was released in January last year and returned to the United States, where his wife has filed for divorce.

Maryam's hunger strike last year lasted 27 days. She stopped after she was told she would be released, but as yet there seems to be little sign of that.

The Israeli prime minister Benjamin Netanyahu yesterday told a group of Christian media representatives that Israel has no better friend than the world's Christian communities. The message has caused criticism from the mayor of Bethlehem.